Objective: To investigate how gestational age and prior vaginal birth affect cervical anatomy on magnetic resonance imaging during pregnancy. Study design: Magnetic resonance images of the cervix were obtained in cons...Objective: To investigate how gestational age and prior vaginal birth affect cervical anatomy on magnetic resonance imaging during pregnancy. Study design: Magnetic resonance images of the cervix were obtained in consecutive patients referred for a suspected fetal abnormality. We used an image processing protocol to measure cervical dimensions, orientation, and signal intensity. We determined how outcome variables were affected by gestational age and prior vaginal birth. Results: Adequate images were obtained in 53 of 57 patients at 17 to 36 weeks. As gestational age increased by 12 weeks, the mean cross-sectional area of the cervical canal and cervical stroma increased 31%(95%confidence interval 0%to 73%) and 31%(95%confidence interval 11%to 55%), respectively. The normalized signal intensity of the stroma increased from 0.83 (95%confidence interval 0.81 to 0.85) at 20 weeks to 0.91 (95%confidence interval 0.88 to 0.94) at 32 weeks. None of the outcome variables were affected by prior vaginal birth. Conclusion: Magnetic resonance imaging revealed that cross-sectional area and signal intensity of the cervical stroma increase with increasing gestational age.展开更多
Early preterm birth at 20 to 26 weeks of gestation (periviable birth) carries extreme risks of infant death and morbidities. Prevention of periviable birth could improve infant outcomes significantly. We sought to cha...Early preterm birth at 20 to 26 weeks of gestation (periviable birth) carries extreme risks of infant death and morbidities. Prevention of periviable birth could improve infant outcomes significantly. We sought to characterize the causes of periviable birth and to determine whether periviable birth can be predicted by previous pregnancy outcome. Study design: We evaluated 104,921 pregnancies (1974- 2004) and assessed the frequency and causes of periviable birth. Women who were delivered of both their first and second pregnancies at >20 weeks of gestation at our institution were identified. Predictive values of the first pregnancy outcomes for second pregnancy outcomes were determined. Results: Periviable birth complicated 1981 deliveries (1.9% ). Seventy-nine percent of the women with periviable births had no history of periviable births; 44% of the women had no previous deliveries, and 35% of the women had previous term deliveries only. Causes of periviable birth were labor (36% ), premature rupture of membranes (34% ), bleeding (10% ), and preeclampsia (4% ). Four percent of the gestations were multiple gestations. Among 7970 pregnancies at >20 weeks of gestation, periviable birth in the first pregnancy was associated with preterm birth and periviable birth in the second pregnancy (35.6% , 6.9% ; relative risk, 3.3 and 8.6; P < .0001). Periviable birth and preterm birth in the first pregnancy were insensitive for periviable birth in the second pregnancy (8.8% , 36.8% , respectively). Conclusion: Although periviable birth is associated with subsequent periviable birth and preterm birth, preterm birth and periviable birth are insensitive markers for recurrences in the next pregnancy. Early pregnancy or preconceptional markers for prediction of periviable birth are needed.展开更多
Objective: This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings. Study design: We ...Objective: This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings. Study design: We performed a case-control study nested within a cohort of women who have had a prior cesarean to determine the incidence and risk factors for uterine rupture in women attempting VBAC. Results: The incidence rate of uterine rupture in those who attempt VBAC was 9.8 per 1000. A prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio OR = 0.40, 95%CI 0.20-0.81). Although prostaglandins alone were not associated with uterine rupture, sequential use of prostaglandin and pitocin was associated with uterine rupture (adjusted OR = 3.07, 95%CI 0.98-9.88). Conclusion: Women with a prior cesarean should be offered VBAC, and women with a prior cesarean and prior vaginal delivery should be encouraged to VBAC. Although other studies have suggested that prostaglandins should be avoided, we suggest that inductions requiring sequential agents be avoided.展开更多
Objective Women with endometriosis may be at an in-creased risk of ovarian cancer.It is not known whether reproductive factors that reduce th e risk of ovarian cancer in general also reduce risk in women w ith endomet...Objective Women with endometriosis may be at an in-creased risk of ovarian cancer.It is not known whether reproductive factors that reduce th e risk of ovarian cancer in general also reduce risk in women w ith endometriosis.We investigated whether the odds ratios for ovarian cancer that were associated with oral contr aceptive use,child-bearing,hysterectomy,and tubal ligation differ among women with and without endometriosis.Study design We pooled information on the self -reported history of en-dometriosis from 4population -base d case -controlled studies of incident epithelial ovarian cancer,comprising2098cases and 2953control subjects.We obtained data on oral contraceptive use,childbearing,breastfeeding,gyne-cologic surgical procedures,and other reproductive factors on each woman.Multivariable uncond itional logistic re-gression was used to calculate odds r atios and 95%CI for ovarian cancer amongwomen with endometriosis compared with women without endometriosis.S imilar methods were used to assess the frequencies of ris k factors among women with and without endometriosis.Adj ustments were made for age,parity,oral contraceptive use,tubal ligation,family history of ovarian cancer,and study site.Results Women with endometriosis were at an increa sed risk of ovarian cancer(odds ratio,1.32;95%CI,1.06-1.65).Using oral contraceptives,bearing child ren,and having a tubal ligation or hysterectomy were associated with a similar re-duction in the odds ratios for ovaria n cancer among women with and without endometriosis.In p articular,the use of oral contraceptives for>10years was associated with a substantial reduction in risk among women with en-dometriosis(odds ratio,0.21;95%CI,0.08-0.58).Conclusion Women with endometriosis are at an increased risk of epithelial ovarian cancer.L ong -term oral contra-ceptive use may provide substantial protection against the disease in this high -risk population.展开更多
文摘Objective: To investigate how gestational age and prior vaginal birth affect cervical anatomy on magnetic resonance imaging during pregnancy. Study design: Magnetic resonance images of the cervix were obtained in consecutive patients referred for a suspected fetal abnormality. We used an image processing protocol to measure cervical dimensions, orientation, and signal intensity. We determined how outcome variables were affected by gestational age and prior vaginal birth. Results: Adequate images were obtained in 53 of 57 patients at 17 to 36 weeks. As gestational age increased by 12 weeks, the mean cross-sectional area of the cervical canal and cervical stroma increased 31%(95%confidence interval 0%to 73%) and 31%(95%confidence interval 11%to 55%), respectively. The normalized signal intensity of the stroma increased from 0.83 (95%confidence interval 0.81 to 0.85) at 20 weeks to 0.91 (95%confidence interval 0.88 to 0.94) at 32 weeks. None of the outcome variables were affected by prior vaginal birth. Conclusion: Magnetic resonance imaging revealed that cross-sectional area and signal intensity of the cervical stroma increase with increasing gestational age.
文摘Early preterm birth at 20 to 26 weeks of gestation (periviable birth) carries extreme risks of infant death and morbidities. Prevention of periviable birth could improve infant outcomes significantly. We sought to characterize the causes of periviable birth and to determine whether periviable birth can be predicted by previous pregnancy outcome. Study design: We evaluated 104,921 pregnancies (1974- 2004) and assessed the frequency and causes of periviable birth. Women who were delivered of both their first and second pregnancies at >20 weeks of gestation at our institution were identified. Predictive values of the first pregnancy outcomes for second pregnancy outcomes were determined. Results: Periviable birth complicated 1981 deliveries (1.9% ). Seventy-nine percent of the women with periviable births had no history of periviable births; 44% of the women had no previous deliveries, and 35% of the women had previous term deliveries only. Causes of periviable birth were labor (36% ), premature rupture of membranes (34% ), bleeding (10% ), and preeclampsia (4% ). Four percent of the gestations were multiple gestations. Among 7970 pregnancies at >20 weeks of gestation, periviable birth in the first pregnancy was associated with preterm birth and periviable birth in the second pregnancy (35.6% , 6.9% ; relative risk, 3.3 and 8.6; P < .0001). Periviable birth and preterm birth in the first pregnancy were insensitive for periviable birth in the second pregnancy (8.8% , 36.8% , respectively). Conclusion: Although periviable birth is associated with subsequent periviable birth and preterm birth, preterm birth and periviable birth are insensitive markers for recurrences in the next pregnancy. Early pregnancy or preconceptional markers for prediction of periviable birth are needed.
文摘Objective: This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings. Study design: We performed a case-control study nested within a cohort of women who have had a prior cesarean to determine the incidence and risk factors for uterine rupture in women attempting VBAC. Results: The incidence rate of uterine rupture in those who attempt VBAC was 9.8 per 1000. A prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio OR = 0.40, 95%CI 0.20-0.81). Although prostaglandins alone were not associated with uterine rupture, sequential use of prostaglandin and pitocin was associated with uterine rupture (adjusted OR = 3.07, 95%CI 0.98-9.88). Conclusion: Women with a prior cesarean should be offered VBAC, and women with a prior cesarean and prior vaginal delivery should be encouraged to VBAC. Although other studies have suggested that prostaglandins should be avoided, we suggest that inductions requiring sequential agents be avoided.
文摘Objective Women with endometriosis may be at an in-creased risk of ovarian cancer.It is not known whether reproductive factors that reduce th e risk of ovarian cancer in general also reduce risk in women w ith endometriosis.We investigated whether the odds ratios for ovarian cancer that were associated with oral contr aceptive use,child-bearing,hysterectomy,and tubal ligation differ among women with and without endometriosis.Study design We pooled information on the self -reported history of en-dometriosis from 4population -base d case -controlled studies of incident epithelial ovarian cancer,comprising2098cases and 2953control subjects.We obtained data on oral contraceptive use,childbearing,breastfeeding,gyne-cologic surgical procedures,and other reproductive factors on each woman.Multivariable uncond itional logistic re-gression was used to calculate odds r atios and 95%CI for ovarian cancer amongwomen with endometriosis compared with women without endometriosis.S imilar methods were used to assess the frequencies of ris k factors among women with and without endometriosis.Adj ustments were made for age,parity,oral contraceptive use,tubal ligation,family history of ovarian cancer,and study site.Results Women with endometriosis were at an increa sed risk of ovarian cancer(odds ratio,1.32;95%CI,1.06-1.65).Using oral contraceptives,bearing child ren,and having a tubal ligation or hysterectomy were associated with a similar re-duction in the odds ratios for ovaria n cancer among women with and without endometriosis.In p articular,the use of oral contraceptives for>10years was associated with a substantial reduction in risk among women with en-dometriosis(odds ratio,0.21;95%CI,0.08-0.58).Conclusion Women with endometriosis are at an increased risk of epithelial ovarian cancer.L ong -term oral contra-ceptive use may provide substantial protection against the disease in this high -risk population.
